Have never finished GTA: SA itself but the multiplayer is awesome. So many game modes possible!
Don't really know how much time I spent on it but I remember starting playing it when I was 15 all the way until becoming 18 years of age..

cudiedgar
Well unlike other games of same genre, rounds are short, there are no items, a lot really a lot of AOE madness, crazy variation of maps with epic monsters... These are my arguments to back up the statement its MOBA on steroids(since I played others, and none were addictive and good as this). Hopefully now you understand. But hey this is just my subjective opinion.

I've gotta say that - World of Warcraft, is the game who has stole most time of my life, other than my GF . I haven't played it recently, but it definately tops my list.
These days I'm more into CSGO, BF4 and that kind of stuff other than anything else.

TERA. Took eons to download just to be removed because of failure applying patch and all gameforge launcher madness. If you are like me(from Europe), I suggest you don't even bother downloading. Launcher is bugged. Took my space up to 54 GB overwriting itself(and didn't stop)....

31 hours and counting (according to Steam).
Everytime I need to format a computer (or change to a new one) I forget to backup the save file and need to start from scratch :/ Now aiming to get 100% completion.

Also Terraria, League of Legends (you can tell from my avatar), Transistor, Hotline Miami 2 aaaaaaaaaaand that's about it.